The reaction between an un-functionalized conjugated diene and a nitroarene under CO pressure, catalyzed by Ru-3(CO)(12)/Ar-BIAN (Ar-BUN = bis(arylimino)acenaphthene), affords the corresponding allylic amine (1), the hetero-Diels-Alder adduct (oxazine) (2), and the N-arylpyrrole (3) in different ratios depending on the experimental conditions. The synthesis of the allylic amine involves an intermolecular catalytic C-H functionalization by a transition metal complex. Compounds I and 2 are primary products of the reaction, whereas 3 derives from a following reaction of 2. By running the reaction at 120 degreesC, the decomposition of 2 to 3 is completely suppressed, allowing for the isolation of 2 in good yields. On the contrary, at 200 degreesC 2 is completely transformed into 3 during the reaction. The selectivity in allylic amine is somewhat sensitive to the experimental conditions and always ranges between 15 and 25%. Electron-withdrawing substituents on the nitroarene give better results, but electron-donating ones slow the reaction and give lower selectivities. Steric hindrance on the nitroarene strongly retards the reaction, but use of 2-methylnitrobenzene allowed for the isolation and X-ray structural characterization of a resting state of the catalytic system, Ru[N(o-CH3C6H4)C(O)N(o-CH3C6H4)C(O)](CO)(2)(Ph-BIAN) (9).
Synthesis of N-arylpyrroles, hetero-Diels-Alder adducts, and allylic amines by reaction of unfunctionalized dienes with nitroarenes and carbon monoxide, catalyzed by Ru(CO)(3)(Ar-BIAN) / F. Ragaini, S. Cenini, E. Borsani, M. Dompe, E. Gallo, M. Moret. - In: ORGANOMETALLICS. - ISSN 0276-7333. - 20:16(2001), pp. 3390-3398.
|Titolo:||Synthesis of N-arylpyrroles, hetero-Diels-Alder adducts, and allylic amines by reaction of unfunctionalized dienes with nitroarenes and carbon monoxide, catalyzed by Ru(CO)(3)(Ar-BIAN)|
RAGAINI, FABIO ATTILIO CIRILLO (Primo)
CENINI, SERGIO (Secondo)
GALLO, EMMA (Penultimo)
|Parole Chiave:||Bidentate nitrogen ligands; C-H functionalization; aromatic heterocycles; rutheinium complexes; amination; carbonylation; palladium; alkenes; nitroaromatics; coordination|
|Settore Scientifico Disciplinare:||Settore CHIM/03 - Chimica Generale e Inorganica|
|Data di pubblicazione:||2001|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1021/om010076j|
|Appare nelle tipologie:||01 - Articolo su periodico|